Symbol Selenium (Se)-80 mass number 80 #of electrons 34 #of protons 34 of neutrons 46 113 Cd 2+ 113 Ne
The Correct Answer and Explanation is:
Corrected Answers:
- Selenium (Se-80):
- Mass number: 80
- Number of protons: 34
- Number of electrons: 34
- Number of neutrons: 46
- Cadmium ion (Cd²⁺-113):
- Mass number: 113
- Number of protons: 48
- Number of electrons: 46 (due to the 2+ charge)
- Number of neutrons: 65
- Neon atom (Ne-20):
- Mass number: 20
- Number of protons: 10
- Number of electrons: 10
- Number of neutrons: 10
Explanation
Atoms are composed of three subatomic particles: protons, neutrons, and electrons. The number of protons determines the element’s identity and is known as the atomic number. Neutrons are neutral particles that, along with protons, contribute to an atom’s mass number. Electrons are negatively charged particles that orbit the nucleus and are usually equal in number to protons in a neutral atom.
In the case of Selenium-80, the atomic number is 34, which means it has 34 protons. Since it is a neutral atom, the number of electrons is also 34. The mass number is 80, which is the sum of protons and neutrons. Therefore, the number of neutrons is 80 minus 34, which equals 46.
For Cadmium-113 ion (Cd²⁺), the atomic number of cadmium is 48, so it has 48 protons. The ion has a 2+ charge, meaning it has lost two electrons. As a result, the number of electrons is 46. The mass number is 113, so the number of neutrons is 113 minus 48, which equals 65.
In the case of Neon-20, neon has an atomic number of 10, meaning it has 10 protons. Since it is neutral, it also has 10 electrons. The mass number is 20, so the number of neutrons is 20 minus 10, which equals 10.
Understanding atomic structure is essential in chemistry. It helps explain how atoms interact, form bonds, and behave in different states and reactions. Knowing how to calculate subatomic particles also helps in identifying isotopes and ions accurately.
